The disclosure discloses an ultrasonic sensing device, including a first shell portion, a second shell portion and an ultrasonic sensor. The first shell portion has a first through hole. The first through hole includes a first opening and a second opening. The second shell portion has a second through hole. The second through hole includes a third opening and a fourth opening. The ultrasonic sensor includes a transmitting unit and a receiving unit. The transmitting unit is coupled to the first opening. The receiving unit is coupled to the third opening. At least one of the second opening and the fourth opening is elongated. The ultrasonic sensing device greatly reduces the direct transmission of ultrasonic wave from the transmitting unit to the receiving unit.